Martin Johnson may or may not know the shape of his elite World Cup starting team – his thoughts on this seem as dark and impenetrable as a Leicester maul – but he pretty much knows the make-up of the 30-man party, give or take the odd scrum-half, who will fly to New Zealand later this month.

Wales? They are in a different place, hence the fact that this afternoon's warm-up match between the two countries at the Millennium Stadium is more about the Red Dragon than the red rose.

Should Warren Gatland, the long-time All Black hooker who has been coaching Wales since shortly after the last World Cup in 2007, take a punt on the celebrity centre Gavin Henson, who has yet to reveal to everyone's satisfaction a rediscovered enthusiasm for top-level rugby to rival his passion for reality television? We will be given a clue today when Henson lines up alongside Jamie Roberts in the home midfield.

That midfield will also feature Rhys Priestland, the Scarlets outside-half, in the fabled No 10 jersey. It was Priestland who stepped into the breach at the last moment when Stephen Jones, more experienced to the tune of almost 100 caps, did himself a mischief a few minutes before last week's meeting at Twickenham, and in so doing, he changed Gatland's thinking about the crucial pivot position. "I was very impressed with Rhys," the coach said after the game. "I now have to answer fresh questions about who our best No 10 might be."

The Priestland-Henson-Roberts axis is, in theory at least, packed with attacking potential. Mike Tindall, the gnarled old England centre who pocketed a World Cup winner's medal in 2003 and will lead the visitors today in the absence of the injured Lewis Moody, was certainly conscious of the threat when he chewed the fat yesterday.

"It will be interesting to see how that combination works for them, and interesting to see how we handle it," he said. "There are shifting trends in midfield at international level. Roberts is a very strong all-round player at inside centre, but by moving him to the outside position and bringing in Henson, who is probably more of a ball-player, the balance has changed. We need to put pressure on their 10-12 partnership if we want to take Roberts out of the game."

There will be an equally intense focus on the performance of the new Welsh hooker Lloyd Burns, especially as the World Cup chances of the number one No 2 – the Lions incumbent and recent national captain Matthew Rees – appear to be diminishing by the press conference, if not by the day. Early this week, the Red Dragons' forwards coach, Robin McBryde, himself one of the hooking breed, indicated that Rees would travel injured if necessary. Now, the Welsh hierarchy are talking about losing him to immediate surgery.

So it is down to Burns, a 26-year-old Newport Gwent Dragons player who has yet to taste victory at Test level, to make some sense of the front-row chores – something that has been entirely beyond the Welsh front-row brigade since the injury-enforced break-up of their outstanding Lions unit: Rees, propped by the loose-head specialist Gethin Jenkins and the tight-head operator Adam Jones. It is a big ask, even for someone born in Pontypool, which spawned the celebrated "Viet Gwent" threesome of Charlie Faulkner, Bobby Windsor and Graham Price.

Burns was working as a bricklayer and playing amateur rugby this time last year. He suddenly found himself laying bricks of a different kind when, after a sharp upturn in fortunes, he was called into the Wales squad for a match with the Barbarians earlier this summer. The day before the game, he was married. "I drank squash all day and all night: I didn't touch a drop of alcohol," he said. "We're still waiting for our honeymoon."

England are also in a waiting situation. Chris Ashton, who scored two tries here to secure a fine red rose victory in the first match of last season's Six Nations, has no more than a 30 per cent chance of taking his place on the right wing after rolling an ankle in training. If he fails a fitness test this morning, Matt Banahan of Bath is likely to start, with Delon Armitage of London Irish filling the gap on the bench.

Under tournament conditions, Johnson would no doubt press the Northampton strike runner to play. He is, after all, one of the few Englishmen obviously equipped to score a try from a distance greater than five metres. But this is a shakedown fixture, not a championship match. It would be utter folly for the manager to risk Ashton if there is the slightest question over his fitness. The wing undeniably needs some rugby, having spent the last few weeks recovering from a knee operation and doing rather less on the training field than his peers. What he does not need is a fresh orthopaedic calamity, however minor. Ultimately, it is what Johnson would call a "no-brainer".

Regardless of who starts on the wing, 13 of the England starting line-up can pretty much consider themselves New Zealand-bound. The players playing for their tickets are Richard Wigglesworth, the Saracens half-back, and Hendre Fourie, the open-side flanker who left Leeds for Sale at the end of the last Premiership campaign. The former has moved ahead of the young Wasps player Joe Simpson in the No 9 pecking order while the latter is, according to Johnson, "in the best shape of his life".

Because of Ben Foden's positional versatility – the first-choice full-back has rich experience as a scrum-half – it may be that England will take only two specialist No 9s to All Black country. On the face of it, that would rule Wigglesworth out of the running, given his rating behind Ben Youngs and Danny Care. But Youngs, one of several players to have undergone knee surgery recently, is still struggling for fitness, and if his problems continue, Johnson may feel the need of some safety in numbers.

Fourie, highly effective as a ball-winning breakaway the season before last and now coming to terms with the change in refereeing interpretations at the tackle area that queered his pitch a year ago, has this opportunity to secure the last place in the back-five forwards. "The interpretation change did have an effect, but people like Richie McCaw (the great All Black open-side flanker) and David Pocock (the high-calibre Wallaby) are still doing what they do, and if you have a good player of that type, there's definitely a value," Johnson said.

Wales are most in need of victory. Johnson has been hinting at this all week. But England, who travel to Ireland for their final warm-up a fortnight today and will be at significant risk of defeat there, would rather not start the World Cup on the back of two losses.

As Tindall said: "Teams generally find out where they are by playing away." If they draw a blank this afternoon, the effect could prove significant in the fullness of time.